Return probe defer if requesting a dma channel without a dma controller probed.
Signed-off-by: Ludovic Desroches <[email protected]> --- drivers/spi/spi-atmel.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index f1760fa..62c293d 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -424,14 +424,23 @@ static int atmel_spi_configure_dma(struct atmel_spi *as) dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); - as->dma.chan_tx = dma_request_slave_channel(dev, "tx"); - if (!as->dma.chan_tx) { + as->dma.chan_tx = dma_request_slave_channel_reason(dev, "tx"); + if (IS_ERR(as->dma.chan_tx)) { + err = PTR_ERR(as->dma.chan_tx); + if (err == -EPROBE_DEFER) { + dev_warn(dev, "no DMA channel available at the moment\n"); + return err; + } dev_err(dev, "DMA TX channel not available, SPI unable to use DMA\n"); err = -EBUSY; goto error; } + /* + * No reason to check EPROBE_DEFER here since we have already requested + * tx channel. If it fails here, it's for another reason. + */ as->dma.chan_rx = dma_request_slave_channel(dev, "rx"); if (!as->dma.chan_rx) { @@ -453,7 +462,7 @@ static int atmel_spi_configure_dma(struct atmel_spi *as) error: if (as->dma.chan_rx) dma_release_channel(as->dma.chan_rx); - if (as->dma.chan_tx) + if (!IS_ERR(as->dma.chan_tx)) dma_release_channel(as->dma.chan_tx); return err; } @@ -1324,8 +1333,11 @@ static int atmel_spi_probe(struct platform_device *pdev) as->use_dma = false; as->use_pdc = false; if (as->caps.has_dma_support) { - if (atmel_spi_configure_dma(as) == 0) + ret = atmel_spi_configure_dma(as); + if (ret == 0) as->use_dma = true; + else if (ret == -EPROBE_DEFER) + return ret; } else { as->use_pdc = true; } -- 2.0.3 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
